Causes

Polyps of the colon and rectum are most often benign. This means they are not a cancer and do not spread. You may have one or many polyps. They become more common with age. There are many types of polyps.

Adenomatous polyps are a common type. They are gland-like growths that develop on the mucous membrane that lines the large intestine. They are also called adenomas and are most often one of the following:

Tubular polyp, which protrudes out in the lumen (open space) of the colon

Villous adenoma, which is sometimes flat and spreading, and is more likely to become a cancer

When adenomas become cancerous, they are known as adenocarcinomas. Adenocarcinomas are cancers that originate in glandular tissue cells. Adenocarcinoma is the most common type of colorectal cancer.

Other types of polyps are:

Hyperplastic polyp, which rarely, if ever, develop into cancer

Serrated polyp, which is less common, but may develop into cancer over time

Treatment

Colorectal polyps should be removed because some can develop into cancer. In most cases, the polyps may be removed during a colonoscopy.

For people with adenomatous polyps, new polyps can appear in the future. You should have a repeat colonoscopy usually 1 to 10 years later, depending on:

Your age and general health

Number of polyps you had

Size and type of the polyps

Family history of polyps or cancer

In rare cases, when polyps are very likely to turn into cancer or too large to remove during colonoscopy, the doctor will recommend a colectomy. This is surgery to remove part of the colon that has the polyps.

Outlook (Prognosis)

Outlook is excellent if the polyps are removed. Polyps that are not removed can develop into cancer over time.

These tests help prevent colon cancer by finding and removing polyps before they become cancer. This may reduce the chance of developing colon cancer, or at least help catch it in its most treatable stage.

Most people should begin these tests at age 50. Those with a family history of colon cancer or colon polyps may need to be screened at an earlier age or more often.

Taking aspirin, naproxen, ibuprofen, or similar medicines may help reduce the risk for new polyps. Be aware that these medicines can have serious side effects if taken for a long time. Side effects include bleeding in the stomach or colon and heart disease. Talk with your provider before taking these medicines.